Loading...
Search for:
a-posteriori
0.007 seconds
Metaphysical necessity in the neo-sadraian school and assessment of necessitarian theories of the laws of nature
, Article Teorie Vedy / Theory of Science ; Volume 43, Issue 1 , 2021 , Pages 33-57 ; 12100250 (ISSN) ; Sharif University of Technology
Czech Academy of Sciences
2021
Abstract
To differentiate between the laws of nature and accidental generalizations, we must adopt a view of necessity that is capable of being realized in relationships existing among natural objects. In neo-Sadraian Islamic philosophy, metaphysical necessity is accepted as part of the cause-effect relationship. This paper compares the neo-Sadraian interpretation of necessity and necessitarian theories about the laws of nature, particularly essentialism and universal theory. By resorting to specific forms al-shûrat al-naw’iyyah, the origin of the essential properties of natural objects, I argue that neo-Sadraians have proposed a perspective on metaphysical necessity that is epistemologically a...
Metaphysical necessity in the neo-sadraian school and assessment of necessitarian theories of the laws of nature
, Article Teorie Vedy / Theory of Science ; Volume 43, Issue 1 , 2021 , Pages 33-57 ; 12100250 (ISSN) ; Sharif University of Technology
Czech Academy of Sciences
2021
Abstract
To differentiate between the laws of nature and accidental generalizations, we must adopt a view of necessity that is capable of being realized in relationships existing among natural objects. In neo-Sadraian Islamic philosophy, metaphysical necessity is accepted as part of the cause-effect relationship. This paper compares the neo-Sadraian interpretation of necessity and necessitarian theories about the laws of nature, particularly essentialism and universal theory. By resorting to specific forms al-shûrat al-naw’iyyah, the origin of the essential properties of natural objects, I argue that neo-Sadraians have proposed a perspective on metaphysical necessity that is epistemologically a...
Investigating the Modal Status and the Epistemological Status of Identity Propositions of Proper Names According to the Kripke’s Doctrines
, M.Sc. Thesis Sharif University of Technology ; Azadegan, Ebrahim (Supervisor)
Abstract
In Naming and Necessity and Identity and Necessity, Kripke convinced many that there are necessary propositions which are knowable only a posteriori. Kripke’s examples of these propositions can be placed into three categories: 1) Some mathematical propositions like Goldbach’s conjecture (the conjecture that every even integer greater than 2 can be expressed as the sum of two primes) 2) Scientific truths like “Water is H2O”, “Gold has the atomic number 79”, etc. 3) Identity statements flanked on both sides with proper names; like “Hesperus is Phosphorus”, “Cicero is Tully” and the like (in the rest of this article, these three categories will be called, respectively, the first, the second and...
Survey on Incompatibility between Content Externalism and Privileged Access to Mental States
, M.Sc. Thesis Sharif University of Technology ; Azadegan, Ebrahim (Supervisor)
Abstract
Content-Externalism is the view according to which, content of mental states are determined by relation that the person has with his environment and content of mental states does not depend on intrinsic properties of subjects. According to this view, if two persons with exactly same intrinsic properties were in different environments, contents of their mental states would be different. On the other hand, the doctrine of privileged access to mental states asserts that if cognitive faculty is functioning properly, then subject can know the content of his mental states a priori. Many critics of externalism believes that accepting externalism along with privileged access terminate to...
The Evolution of a Geometric Space in in the Nineteenth Century
, M.Sc. Thesis Sharif University of Technology ; Shahshahani, Siavash (Supervisor)
Abstract
The meaning and the nature of space and it’s essential properties seems to be one of the oldest problems which has been continuing to occupy human’s mind during centuries. It can be counted as a common ground between philosophy, mathematics, physics and even art. However this thesis concentrates on the philosophical and mathematical attitudes, neglecting the other aspects of the issue. Prima facie, it appears that the concept of space is essentially mingled with geometry, the science which seems to investigate the essentials of space. Taking it for granted, Kant regarded space, and so Euclidean geometry which dominates it, as an indispensible and necessary structure of the human’s mind....
Performance improvement of spread spectrum additive data hiding over codec-distorted voice channels
, Article European Signal Processing Conference ; Volume. 97, Issue. 9 , 2014 , pp. 2510-2514 ; ISSN: 22195491 ; Kazemi, R ; Behnia, F ; Akhaee, M. A ; Sharif University of Technology
Abstract
This paper considers the problem of covert communication through dedicated voice channels by embedding secure data in the cover speech signal utilizing spread spectrum additive data hiding. The cover speech signal is modeled by a Generalized Gaussian (GGD) random variable and the Maximum A Posteriori (MAP) detector for extraction of the covert message is designed and its reliable performance is verified both analytically and by simulations. The idea of adaptive estimation of detector parameters is proposed to improve detector performance and overcome voice non-stationarity. The detector's bit error rate (BER) is investigated for both blind and semi-blind cases in which the GGD shape...
Capacity achieving linear codes with random binary sparse generating matrices over the binary symmetric channel
, Article IEEE International Symposium on Information Theory - Proceedings ; 2012 , Pages 621-625 ; 9781467325790 (ISBN) ; Abadi, H. K ; Pad, P ; Saeedi, H ; Marvasti, F ; Alishahi, K ; Sharif University of Technology
IEEE
2012
Abstract
In this paper, we prove the existence of capacity achieving linear codes with random binary sparse generating matrices over the Binary Symmetric Channel (BSC). The results on the existence of capacity achieving linear codes in the literature are limited to the random binary codes with equal probability generating matrix elements and sparse parity-check matrices. Moreover, the codes with sparse generating matrices reported in the literature are not proved to be capacity achieving for channels other than Binary Erasure Channel. As opposed to the existing results in the literature, which are based on optimal maximum a posteriori decoders, the proposed approach is based on a different decoder...
Optimum detection and location estimation of target lines in the range-time space of a search radar
, Article Aerospace Science and Technology ; Volume 15, Issue 8 , 2011 , Pages 627-634 ; 12709638 (ISSN) ; Sharify, S ; Nayebi, M. M ; Sharif University of Technology
2011
Abstract
The average likelihood ratio detector is derived as the optimum detector for detecting a target line with unknown normal parameters in the range-time data space of a search radar, which is corrupted by Gaussian noise. The receiver operation characteristics of this optimum detector is derived to evaluate its performance improvement in comparison with the Hough detector, which uses the return signal of several successive scans to achieve a non-coherent integration improvement and get a better performance than the conventional detector. This comparison, which is done through analytic derivations and also through simulation results, shows that the average likelihood ratio detector has a better...
Simplified MAP-MUD for active user CDMA
, Article IEEE Communications Letters ; Volume 15, Issue 6 , April , 2011 , Pages 599-601 ; 10897798 (ISSN) ; Mousavi, A ; Goli, A ; Marvasti, F ; Sharif University of Technology
2011
Abstract
In CDMA systems with variable number of users, the decoder consists of two stages. The first stage is the active user identification and the second one is the multi-user detection. Most of the proposed active user identification methods fail to work in overloaded CDMA systems (when the number of users is more than the spreading factor). In this paper we propose a joint active user identification and multi-user detection for binary input CDMA systems using the Viterbi algorithm. We will show that the proposed identification/detection method is Maximum A posteriori Probability (MAP) and outperforms the pervious results. In addition, some suboptimum decoders will be proposed that have lower...
A MAP-Based order estimation procedure for Sparse channel estimation
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 25 2015 through 28 August 2015 ; Volume 9237 , August , 2015 , Pages 344-351 ; 03029743 (ISSN) ; 9783319224817 (ISBN) ; Babaie Zadeh, M ; Jutten, C ; Sharif University of Technology
Springer Verlag
2015
Abstract
Recently, there has been a growing interest in estimation of sparse channels as they are observed in underwater acoustic and ultrawideband channels. In this paper we present a new Bayesian sparse channel estimation (SCE) algorithm that, unlike traditional SCE methods, exploits noise statistical information to improve the estimates. The proposed method uses approximate maximum a posteriori probability (MAP) to detect the non-zero channel tap locations while least square estimation is used to determine the values of the channel taps. Computer simulations shows that the proposed algorithm outperforms the existing algorithms in terms of normalized mean squared error (NMSE) and approaches...
An alternating minimization method for sparse channel estimation
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 27 September 2010 through 30 September 2010, St. Malo ; Volume 6365 LNCS , 2010 , Pages 319-327 ; 03029743 (ISSN) ; 364215994X (ISBN) ; Babaie Zadeh, M ; Jutten, C ; Sharif University of Technology
2010
Abstract
The problem of estimating a sparse channel, i.e. a channel with a few non-zero taps, appears in many fields of communication including acoustic underwater or wireless transmissions. In this paper, we have developed an algorithm based on Iterative Alternating Minimization technique which iteratively detects the location and the value of the channel taps. In fact, at each iteration we use an approximate Maximum A posteriori Probability (MAP) scheme for detection of the taps, while a least square method is used for estimating the values of the taps at each iteration. For approximate MAP detection, we have proposed three different methods leading to three variants for our algorithm. Finally, we...
Sparse component analysis in presence of noise using an iterative EM-MAP algorithm
, Article 7th International Conference on Independent Component Analysis (ICA) and Source Separation, ICA 2007, London, 9 September 2007 through 12 September 2007 ; Volume 4666 LNCS , 2007 , Pages 438-445 ; 03029743 (ISSN); 9783540744931 (ISBN) ; Babaie Zadeh, M ; Mohimani, G. H ; Jutten, C ; Sharif University of Technology
Springer Verlag
2007
Abstract
In this paper, a new algorithm for source recovery in under-determined Sparse Component Analysis (SCA) or atomic decomposition on over-complete dictionaries is presented in the noisy case. The algorithm is essentially a method for obtaining sufficiently sparse solutions of under-determined systems of linear equations with additive Gaussian noise. The method is based on iterative Expectation-Maximization of a Maximum A Posteriori estimation of sources (EM-MAP) and a new steepest-descent method is introduced for the optimization in the Mstep. The solution obtained by the proposed algorithm is compared to the minimum ℓ1-norm solution achieved by Linear Programming (LP). It is experimentally...
On molecular flow velocity meters
, Article IEEE Transactions on Molecular, Biological, and Multi-Scale Communications ; Volume 7, Issue 4 , 2021 , Pages 224-238 ; 23327804 (ISSN) ; Mirmohseni, M ; Nasiri Kenari, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Flow velocity is an important characteristic of the fluidic mediums. In this article, we introduce a molecular based flow velocity meter consisting of a molecule releasing node and a receiver that counts these molecules. We consider both flow velocity detection and estimation problems, which are employed in different applications. For the flow velocity detection, we obtain the maximum a posteriori (MAP) decision rule. To analyze the performance of the proposed flow velocity detector, we obtain the error probability, its Gaussian approximation and Chernoff information (CI) upper bound, and investigate the optimum and sub-optimum sampling times accordingly. We show that, for binary hypothesis,...
An iterative bayesian algorithm for sparse component analysis in presence of noise
, Article IEEE Transactions on Signal Processing ; Volume 57, Issue 11 , 2009 , Pages 4378-4390 ; 1053587X (ISSN) ; Babaie Zadeh, M ; Jutten, C ; Sharif University of Technology
2009
Abstract
We present a Bayesian approach for Sparse Component Analysis (SCA) in the noisy case. The algorithm is essentially a method for obtaining sufficiently sparse solutions of underdetermined systems of linear equations with additive Gaussian noise. In general, an underdetermined system of linear equations has infinitely many solutions. However, it has been shown that sufficiently sparse solutions can be uniquely identified. Our main objective is to find this unique solution. Our method is based on a novel estimation of source parameters and maximum a posteriori (MAP) estimation of sources. To tackle the great complexity of the MAP algorithm (when the number of sources and mixtures become large),...